main.js

const addInput = document.getElementById("add_input");
const itemsList = document.getElementById("items_list");

function removeItem(e) {
    const removeParent = e.parentNode;
    removeParent.remove()
}

addInput.addEventListener("keyup", e => {
    const inputValue = addInput.value;
     if (e.keyCode === 13 && inputValue.length > 0) {
        const newItem = document.createElement("li");
        newItem.classList.add("items");
        newItem.innerText = inputValue;

        const delBtn = document.createElement("button");
        delBtn.classList.add("del_btn");
        delBtn.setAttribute("key", inputValue);
        delBtn.innerText = "Remove";

        delBtn.setAttribute("onClick", "removeItem(this)");

        newItem.appendChild(delBtn);
        itemsList.appendChild(newItem);

        addInput.value = "";
     }
})